This invention relates to vaccines and particularly to an attenuated, live mumps virus which is to be injected into human beings to protect them against mumps.
This invention concerns a live non-pathogenic attenuated mumps virus and its use as a vaccine which after injection into humans will confer protection against mumps. The clinical features of mumps infection are well documented. The disease is one of childhood and it confers durable immunity. Adults who have escaped childhood exposure can be infected in later life. Any detectable level of antibody is considered protective in man. The attenuated live mumps virus stimulates formation of antibody in humans with no production of clinical illness.
Mumps vaccines and their preparations are, of course, known. U.S. Pat. No. 3,555,149 discloses a live attenuated mumps virus vaccine prepared by growing the virus in at least 10 successive passages in embryonated hens' eggs followed by propagation in chick embryo tissue culture. In contrast thereto, the present invention prepares live mumps virus by growing the virus in three serial passages through primary human amnion tissue cell monolayers followed by one passage in embryonated chicken eggs and by from 8 through 28 serial passages in primary chick embryo tissue cells.